murphy
Hey,
Does anyone know if there is an Elixir module, which detects the correct mime type for uploaded files?
I have some issus in my Phoenix project, for example Firefox sets the mime type for pdf files to
“application/download” instead of “application/pdf”.
So I’m looking for a module or help writing a module which can detect this from [file signatures]
(Redirect to SEARCH...).
Any advice is welcome.
Thanks
Andy
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NobbZ
If you are on a linux host you can probably use
file(with--mime-typeoption) ormimetype.If there is a package available on hex, I’d guess it does wrap one of these.
murphy
that looks good. thanks!
AstonJ
Is Dyanmo’s mime library what you’re looking for?
NobbZ
As I understand @murphy he wants to check the magic number of the file, instead of relying on the file extension (which can be as wrong as anything a browser thinks to set as MIME-type).
Also, because of this thread, I hacked a wrapper which is available as
file_infofrom hex.pm. It is very basic right now, but I do plan to make it better.AstonJ
Ah right, sorry, I didn’t look into the library and wasn’t aware it was relying on file extensions.
Good on you for working on a wrapper
findlaech
Something interesting would be to extract the header of the file and pattern-match it against a pre-defined map of type ↔ headers.
If someone wants to play with bitstrings…
NobbZ
As you can see in issue #4, I do plan in the long term, that I want to remove the necessy of
findbeeing available and to the tests directly on Elixir side, but I really think it will tike quite a while, since there are many MIME-types with many magic numbers.At first I’d need some reliable source of such magic numbers and their mapping to MIME-types.
AstonJ
Is this any good?
murphy
yes i was thinking, that maybe someone has already done this.
But i´m working on linux anyway, so many thanks to @NobbZ for the wrapper.
NobbZ
I will take a closer look later this month if this can help.
I have thought about this, but I don’t think that a sequential pattern match is fast enough. Since these magic numbers are of different length and you only now the length after you had a successfull match, I think some kind of Trie